The central goal of the present research is to relate indices of central nervous system activity (event related brain potentials) and autonomic responses (electrodermal activity) during learning of emotional behavior. The central learning paradigm is that of classical (Pavlovian) conditioning. Simple visual and auditory stimuli are used as conditional stimuli and a sharp noise as unconditioned stimulus. Conditioning parameters, like interstimulus interval and reinforcement probabilities, are manipulated while concurrent measurement is made of autonomic and brain wave variables. Principal interest is in the N2 and P3 components of the early event related brain potential as well as the early and late components (O and E waves) of the contingent negative variation. Predictions tested are about the relations of the EEG measures to specific components of conditioned electrodermal behavior, particularly the anticipatory (or Pre-UCS) response and the UCS-omission response.